What’s Sam Darnold dealing with? ‘Mono’s rough,’ says the only other NFL QB sidelined by it

When Sam Darnold curls up, presumably at his North Jersey apartment, and fires up his TV to watch his New York Jets take the field without him on Monday night, he will join an exclusive club.

A sore, physically sapped, fevered club. A miserable club whose membership count is believed to be two.

“This,” says Chris Chandler, the only other starting NFL QB known to have been sidelined by mononucleosis, “is a legit, hardcore illness.”

Darnold was diagnosed with it on Wednesday, and immediately quarantined in his apartment. He had, according to Jets head coach Adam Gase, already lost five pounds. He had missed practice Wednesday with what Gase originally called strep throat.

But this – mono, as it’s commonly called – is worse. Much worse.

Just ask Chandler, who spoke to Yahoo Sports Thursday from his home in Utah. He contracted the virus midway through a 17-year NFL career, late in the 1995 season.

Following a 42-33 Houston Oilers win over the Denver Broncos, in which he threw for 280 yards and three touchdowns, “I wasn’t feeling real good,” he remembers.

Then came the sore throat. The tiredness. The weakness. The following week, the Oilers went to Pittsburgh. “I didn’t warm up at all,” Chandler recalls. “I actually threw a touchdown pass in the first [half]. And then I went back in the locker room, and I just fell asleep.

“I’ll never forget walking off that field in Pittsburgh,” he continues. “I literally went back to the locker room, on a concrete floor, laid on my back with a towel behind my head, and just fell asleep until the game was over.”

Chandler tried to go again the following week, back at home against Detroit. “I probably shouldn’t have played,” he now admits. He again lasted until halftime, but was replaced by rookie Steve McNair. For two or three weeks thereafter, he did “nothing.” His season, in Week 15, was over.

Chandler still has no idea how he got mono. “I’m not even sure exactly what mono is,” he says. “But it’s definitely a tough thing to deal with.”

What is mono? And why can’t NFL players play with it?

Mono, in short, is a virus transmitted via saliva that can cause fatigue, fevers, swelling and other unsavory symptoms that generally make life wretched.

Another potential symptom is an enlarged spleen. That’s why football players can’t simply fight through mono to take the field. The spleen’s enlargement puts it at risk of rupturing – and puts the players, therefore, at risk of serious injury, or even death.

Very few NFLers have publicly been diagnosed with it. Some, however, understand Darnold’s plight. Former 49ers offensive lineman Jonathan Martin missed OTAs with the illness in 2014. Recently retired defensive end Chris Long was diagnosed with it back in college, and says he lost 20 pounds.

“MISERABLE,” Long wrote on Twitter Thursday. “Couldn’t breathe.”

Other college football players diagnosed with mono had similar experiences.

When Michigan State cornerback Darian Hicks fell ill a few weeks before the opening game of his junior season, he initially assumed he just had a bad sore throat. Only after he woke up one morning with his tonsils inflamed and swollen did he realize it was something worse.

"It's kind of a surreal feeling because you hear about mono but you never think that you're going to get it," Hicks told Yahoo Sports.

For the next couple weeks, Hicks recalls constantly feeling sluggish. He lost 12 pounds because he couldn't eat or drink anything without his body clenching up.

Once Hicks was finally cleared to play after fall camp was over, he struggled to regain the muscle he’d lost. Even so, he persevered, regaining his starting job by midseason, producing a career-best 33 tackles, and helping Michigan State advance to the 2015 College Football Playoff.

"I didn’t let that stop me from making an impact,” Hicks says. "It forced something new out of me. It was a blessing in a curse."

Still, mono is both a draining affliction and a rare one. Darnold’s is just the second known case among NFL starting QBs.

‘This thing will grab you by the throat and throw you down’

“The virus,” according to the Mayo Clinic, “has an incubation period of approximately four to six weeks.” That jibes with Gase’s words Thursday. Darnold, the Jets coach said, will be out indefinitely. With New York on bye in Week 4, Week 5 appears to be the earliest possible return date.

In the meantime, Darnold won’t be able to do much more than ride mono out. Rest. Hydrate. And wait.

EAST RUTHERFORD, NJ - SEPTEMBER 08:  New York Jets quarterback Sam Darnold (14) after the National Football League game between the New York Jets and the Buffalo Bills on September 8, 2019 at MetLife Stadium in East Rutherford, NJ.(Photo by Rich Graessle/Icon Sportswire via Getty Images)
Sam Darnold and the New York Jets lost to the Bills in Week 1. (Getty)

Chandler recalls the commonplace football urge to battle through. To shrug off the symptoms. To play despite them.

“I would assume he probably said, ‘I can do it, I’m fine,’ ” the former Pro Bowler says of Darnold. “But this thing will just grab you by the throat and throw you down on the ground and say, ‘No, you’re not playing.’ ”

The first phase of symptoms, Chandler remembers, were “not necessarily a flu, but you kind of have some body aches, and you just don’t feel great.

“Then, all of a sudden, you can’t even stay awake. When it hits you, there’s no possibility of [playing]. You’re, like, ‘Down goes Frazier.’ ”

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Yahoo Sports features writer Jeff Eisenberg contributed to this story.

Henry Bushnell is a features writer for Yahoo Sports. Have a tip? Question? Comment? Email him at, or follow him on Twitter @HenryBushnell, and on Facebook.

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